How does the ASME B30 volume apply to my older crane?

The volume's introduction states that existing equipment is subject to the standard as of the effective date of the standard.

As technology and best practices are implemented in the crane and lifting industry, a question of the status of older equipment often comes up. Does the new standard apply to equipment manufactured or installed before the latest revision?

In short, the answer is 'yes'. For example, the introduction from ASME B30.5, section V describes that existing equipment is subject to the standard as of the standard's effective date.

The caveat is that the standard does not intend for the immediate and automatic retrofitting of equipment in order to remain in compliance.  Instead, when a component requires modification, the new, replacement item must be evaluated by a qualified person and a determination made as to the need to meet the current standard.